[单项选择题] 在窗体上画一个名称为Commana1的命令按钮，然后编写如下程序：Dim SW As Boolean Function func(X As Integer)As Integer

[单项选择题] 在窗体上画一个名称为Commana1的命令按钮，然后编写如下程序：

Dim SW As Boolean

Function func(X As Integer)As Integer

If X＜20 Then

Y=X

Else

Y=20+X

End If

func = Y

End Function

Private Sub Form MouseDown(Button As Integer,_

Shift As Integer,X As Single, Y As Single)

SW = False

End Sub

Private Sub Form_MouseUp( Button As Integer,_

Shift As Integer ,X As Single, Y As Single)

SW = True

End Sub

Private Sub Commandl_Click( )

Dim intNum As Integer

intNum = InputBox(" ")

If SW Then

Print func(intNum)

End If

End Sub

程序运行后，单击命令按钮，将显示一个输入对话框，如果在对话框中输入25，则程序的执行结果为

A．输出0

B．输出25

C．输出45

D．无任何输出

C

本题考查的是鼠标事件，当压下鼠标左键(发生MouseDown时)SW的值为False，当松开鼠标左键(触发MouseUp时)SW的值为True。